Ink jet printers are known and provide a number of advantages in the printing process. For example, ink jet printers are capable of providing relatively high density color output at an acceptable printing speed. Furthermore, such printers are relatively inexpensive. As a result, it is desirable to utilize such printers in the formation of identification cards. Unfortunately, ink from ink jet printers does not adhere well to the plastic surfaces of most identification card substrates, which are typically formed of PVC. Accordingly, it is necessary to create an ink-receptive surface on the identification card substrate to allow it to receive an image printed by an ink-jet printer.
Methods have been used to provide ink jet printable or receptive surfaces on various types of substrates, such as compact discs and identification cards. In general, these methods involve coating the surface with an ink-receptive material. Once coated with the ink-receptive material, the card substrates can be used in identification card printers utilizing ink jet printheads, such as the CardJet 410 printer and encoder manufactured by Fargo Electronics, Inc. of Eden Prairie, Minn. Examples of such ink-receptive materials encoding methods are provided in U.S. Pat. Nos. 6,051,306 and 6,270,858, which issued Apr. 18, 2000 and Aug. 7, 2001, respectively, and are both assigned to Fargo Electronics, Inc.
Ink-receptive films have also been applied to card substrates to form an ink-receptive surface thereon. As illustrated in FIG. 1, such ink-receptive films 10 are formed of a clear or an opaque backing layer (e.g., PET, PVC, etc.) 12, on which an ink-receptive coating 14 is applied. A layer of adhesive 16 is generally applied between the backing layer 12 and a surface 18 of a rigid or semi-rigid card member 20. Card member 20 is a conventional blank card substrate that is typically formed of PVC or other suitable material. A protective cover (not shown) is laid over the ink-receptive coating 14 and the backing layer 12 of the ink-receptive film 10 is laminated to card member 20 through application of heat and pressure. Portions of ink-receptive film 10 that overhang the edges of card member 20 are then trimmed as necessary. A laminate layer 22 can be laminated to a bottom surface 24 of card member 20 by adhesive layer 26 in an effort to counterbalance stresses that are applied to card member 20 as a result of the lamination of backing layer 12 of ink-receptive film 10 to surface 18 of card member 20.
Unfortunately, the above-described process of forming an ink-receptive card substrate using an ink-receptive film is problematic. The layers of adhesive, ink-receptive film, card member, and the laminate, result in a complex and expensive ink-receptive card substrate. Also, the backing layer of the ink-receptive film can potentially delaminate from the card member due to its exposed edges, thereby limiting the useful life span of the ink-receptive card substrate. Additionally, the image that is printed to the ink-receptive surface that is formed by the ink-receptive coating of the film can be easily modified by replacing the printed ink-receptive film with another. As a result, these ink-receptive card substrates are complicated, expensive to form, have a limited life span, and offer little security against alteration.
Images that are printed to ink-receptive surfaces of card substrates that are formed in accordance with the methods described above are susceptible to defacement due to abrasion, exposure to water, and other environmental conditions. Accordingly, a protective overlaminate material must be applied over the printed ink-receptive surface to protect the printed image.